1. Technical Field
Embodiments of the present invention relate to a method of manufacturing a resistance change layer and a method of manufacturing a resistive random access memory device. More specifically, embodiments of the present invention relate to a method of manufacturing a resistance change layer and a method of manufacturing a resistive random access memory device using electron beam irradiation.
2. Related Art
Since the late 1990s, application of memory devices has not been limited to a computer and has been expanded to a variety of electronic products. In addition, various kinds of memory devices are being developed in order to achieve high integration and high response speed.
Among those, a resistive random access memory device, that is, one of non-volatile memory devices is a device using a material capable of switching at least two different resistance states since a resistance rapidly changes depending on an applied voltage. Recently, the resistive random access memory device is in the spotlight for simplicity of a structure, stability, low power consumption, and high response speed, and since it can achieve high integration.
Generally, a resistive random access memory device is formed of a metal/insulator/metal (MIM) structure, and uses a non-volatile “resistance switching” phenomenon.
That is, a resistive random access memory device has two different resistance states at one voltage, and is operated by switching “on” or “off” using a low resistance state (LRS) and a high resistance state (HRS) and thereby storing 2-bit information. In addition, a resistive random access memory device has non-volatile characteristics in which, when a state is once changed, the state is continually maintained even when external power is not supplied, until a next switching occurs.
Depending on the characteristics of “on” or “off” switching operation, there are a unipolar resistive random access memory device in which both two resistance states are switched at one polarity, and a bipolar resistive random access memory device in which two resistance states are switched by changing a voltage polarity.
Currently, a charge trap type NAND flash memory device is difficult to be highly integrated any more due to a limitation in scaling. In addition, since a method in which electrons remain in a charge trap area by a tunneling technique using a tunnel insulating layer requires a high electric field, it is required to control decrease in an operation speed and variation in threshold voltages.
In addition, since a physical environment for manufacturing a highly integrated non-volatile memory device which is stably operated at 20 nm or less, reaches commercial limits, a non-volatile memory device with a different operation mechanism is needed.
In addition, a new manufacturing method is required to easily control a composition ratio of a resistance change layer when the resistance change layer including oxide semiconductors having different composition ratios.